Power-transmission of turbomechanical type



April 6, 1954 c. 1. PLACE POWER-TRANSMISSION OF TURBOMECHANICAL TYPE Filed May 29, 1950 Q an km 1 K W m w 1 m: m N mm & wt Q N m: w? u i N K x mm W L Q M Q 1 7 8 5 Q l .& Q m ms 9v m: & Q g 0% w um 3v N Q mm 0.Q\ mm \K x\ N\ N mm. 9% w mw we w Q Q N 5 a g Q Q mvz/vrora, CHARLES I. PLACE %WEY5 Patented Apr. 6, 1954 MECHANIGAL' -TYPE Charles'I'.-Pla'ce, Norfolk,.Conn..;

Application May 29, 1950,v SeriaINm' 16 L932 v 9 Claims. (Cl. 74'-688)' 1 This invention relates to improvements in power transmissions of turbo-mechanical type, and more particularly to a fully automatic, variable transmission of step-less character, capable of a wide variety of applications, but suitable in particular for use in automotive'vehicles and the like; p

The presently improved turbo-mechanical transmission embodies diiferential gearing including at least two'mutually cooperative gear trains between power input andoutput' memhers or shafts, and a fluid turbine having its impeller in operative connection with one of the gear trains and in driven connectionwith the power input shaft, and the turbine output in planet-gear connection with the power input shaft'and'an elementof the other gear train. The novel arrangementofthe turbine and gearing" is such as to provide'at least two lines of power transmission between the input and output shafts, cooperative to produce. a resultant speed and torque drive of the. driven shaft, wherein the speed and torque of the output shaft varies automatically and smoothly in step-less manner, in response to variations. in. powerapplication to the input shaft and to changes in loading of the output shaft;

objectively stated, one of the principal purposes of the present invention is "to provide. a fully automatic transmission affording a stepless' character of speed and. torque variation produced solely as a result ofchanges. in power input to the transmission and loading of. the

transmission output, thereby avoiding'such gearratio and other control mechanism necessary to the'operation of earlier tra'nsmissi'ohs'as gearshift provisions, brakes and other operatoraotuated controls for rendering elements of the transmission operative or inoperative. to effect speed and torque changes in the transmission.

Another object of'the present'invention is to.

overdrive being effected automatically and under miniinumtorque.requirement of the outputshaft, and occurring, as a normal 7 function of the presentfy improved. transmission"gearinawitliout're uirement'brsu cn 'controlfacilitis as areneces sary to overdriveoperation of" earlier 'forms'o'f' so-called automatic transmissions;

Yet another object is to provide'a fully'automatic transmissionh'aving operating characteristics as hereinabove noted; wherein the trans mission is composed of a desirableminimiiin numberof elements, and presents'a gearing "and" turbine arrangement" capable 'of' compact" assembly: p

Other objects and "advantages of the invention will appear readily upon considerationof' an exemplary embodiment hereinafter described with reference to the'accompanying cira'vi ing,'

tional elevation of the improved transmission.

Referring now to the drawing. which illus tra'tesa presentlypreferred transmission assembly of"improvedcharacter according to'the'p'resent invention, the transmission shown" includes a driving or power input "shaft" It, driven on power output shaft ll, and Ia fluid turbine f2 axially therebetween and" centrally through-the transmission assembly, is as'haft 14''. The end I5 of" shaft I '4 is 'rotatab1y."journalled' in a suit able recess in thee'nd T6 of input shaft I'll, while.

the shaft is further rotatablysupported in a bearing, in the transmission frarneplate IB, a'nd'- has its opposite end 'l9'journalled"inthe' h'ubfZO" ofa drum-like member. 22. The hub 21) ofinember 22 'is rnount ed on'the output shaft l falid.

connected. thereto, as. byfthe key element 21 while theoutputshaft I l isjou'rnalledina hearing in the casing wall 2 I .as' shown.

' The shaft [4' provides. an" operative. support for .the fluidl'turbine lZ W'hich may be of wellknown type suitab'le to the present transmission,

the turbine as here showncomprising a driving. or impeller structure 24,.adriven structure 2 6" anda reactor" 2.1; thereactor including a hubia sleeved onan d' rotatable relative to shaft l4.-

Impeller structure 24 provides an axially/emtended hub sari-say journalled onthe reactor hub 28, and a casing 3| within which-are-the impeller blades 32, the casingproviding, an extension atits open side to. which issecuredfa closure plate 35'carri'ed'b'y the input shaft "I The} 1313176 35 and easin 3 I Yotate with shaft 10;

and hence form the drive connection between shaft In; and the? impellersfl. Driven 'st'ru'cture ZBof thetiirbine" includes a frame' or'cas ing aehavin a nub 38"journal1edi'on'?shaft It,

an'd'a' casing,extension '39providing a spider or planetecarrier 4n havingahiib 42 ournaiieaon the input shaftiend' portion s. spider 4D sup:

- ert-s Stub" snarteifiients" Wen white are to;

tatably mounted the planet gears 44. Engaging the planet gears 44 are a sun gear 46 fixed to or formed as a part of the end I6 of input shaft l0, and an internal ring gear 41 rotatable with shaft 14 through the ring gear spider 48 keyed or otherwise secured to the shaft as shown. The turbine casing 3| and its extension 34, together with the closure plate 35, provide an enclosure within which is a body of fluid such as oil, (not shown), in volume sufficient for the operation of the turbine.

Suitably secured to or keyed on the end [9 of shaft i4, is a spider or planet-carrier 50 supporting stub shaft elements on which rotate planet gears 52. Planet gears 52 engage a sun gear 54 on or integral with one end of a tubular member 55 rotatably sleeved on shaft l4, and also engage an internal ring gear 56 carried by the drum-like member 22 connected to the output shaft ll. Secured to the flange 58 on the rim 59 of member 2 2, as by bolts 60, is a plate or'spider member 62 having a tubular hub 63 rotatably sleeved on the tubular member 55 and further rotatably supportedin a bearing in gear casing frame plate 64. Keyed to hub 63 is a sun gear 66 which engages a gear '61 freely rotatable on a stub shaft 68 fixed to the frame plate 64, as shown. Similarly keyed or otherwise secured to the end 16 of sleeve member 55, is a sun gear II, the latter enmeshing planet gears 12 rotatable on stub shafts 14 supported by a planet-carrier or spider 15. The spider which through its hub 16, is freely rotatably supported on shaft l4, includes a lateral annular projection at its periphery, providing an internal ring gear 18. Engaging the ring gear 16 is a ear 19 keyed to a stub shaft 80, the stub shaftbeing journalled in and projecting through a' bearing portion 82 on frame plate l8. Fixed or keyed to the opposite end of the stub shaft 80, is a gear element 83 which enmeshes a sun gear 84'secured to or formed on the supporting hub of the turbine impeller structure. Completing the differential gearing as above described, is a double internal ring gear member 86 providing ring gear 8! enmeshing the planet gears I2, and a ring gear 88 enmeshing the gear 61. Member 86 includes a central spider support 98 having a hub 9| freely rotatably supported on the sleeve member 55.

Control ofthe turbine reactor 21 such as to prevent reverse rotation thereof during operation of the turbine as a torque-converter, and to permit the reactor to float with the impeller and driven members of the turbine when the turbine acts as a coupling, is here accomplished by a unidirectionalbrake 95 operatively supported on a stub shaft "96 fixed to frame plate 18 and connected to the reactor through a gear 91 engaging a sun gear 98 on the sleeve-hub 28 of the reactor. The uni-directional brake may be of well known form, and is arranged so that its locking action to prevent reverse rotation of the reactor as above indicated, is in proper relation to the normal intended direction of turbine rotation.

Turning now to the operation of the transmission, to facilitate an understanding thereof, let it be assumed that in the embodiment illustrated, the gear ratios are as follows: A gear ratio of one to one obtains between the sun gears 46, 54, I l and their respective planet gears 44, 52, 12; between sun gear 66 and gear 6'1, and between sun gear 84 and gear 83. Further, a gear ratio of one to three obtains in respect to the planet gears 44, 52, I2 and their respective internal ring gears 41, 56, 81'; between gear 61 and ring gear-88, and between gear 19 and ring gear 18. Let it be assumed moreover, that the input shaft 10 is driven from a power source such as an internal combustion engine, having a relatively wide speed range, as from say a low or idling speed of 1200 R. P. M. through a normal operating speed of about 2400 R. P. M. and that the output shaft is connected to a load, as the driving wheels of an automotive vehicle. Now, with the engine idling and rotating the transmission input shaft II] at 1200 R. P. M., in the clockwise direction as shown by the arrow in the figure, and with the output shaft H at rest under load, it will be observed that sun gear 84 rotating clockwise at 1200 R. P. M., turns the gear 83 and hence gear 19, at the same speed but in the counter-clockwise direction. For convenience in the following description, the abbreviation cw. will be employed to denote clockwise rotation and cow. to denote counter-clockwise rotation.

Gear 19 turning ccw. at 1200 R. P. M. as above indicated, drives the ring gear 18 ccw. at onethird the speed of the gear 19 (under the assumed gear ratios), or at 400 R. P. M., and since ring gear 18 is on planet carrier 15, the latter carrying the planet gears 72, will have the same speed cow. Planet gears 12 being in mesh with ring gear 81 and sun gear H, it will appear in view of the assumed gear ratios, that with ring gear 81 at rest, the sun gear ll will be rotated by planet gears 12 at four times the speed of carrier 15, or at 1600 R. P. M. and cow. Conversely, with sun gear I! at rest, the planet gears 12 will rotate ring gear 81 at one and one-third the speed of carrier 15 and ccw. In respect to the latter condition, it will appear further, that should the ring gear 8'! be driven by other than the planet gears at the indicated speed of one and one-third that.

of the carrier 15, the sun gear II will remain at rest.

Since in the example under present discussion, the output shaft l l is at rest under load, the connected ring gear 56 and sun gear 66 will be at rest. It follows then, that gear 61 on fixed shaft 68 and enmeshing sun gear 66 and ring gear 88, will remain at rest and hence retain ring gear 68 at rest. Therefore, since ring gear 81 is on a common carrier with ring gear 88, it will be at rest, thereby establishing the cow. drive of sun gear H by the planet gears 12 at four times the speed of carrier 75, or at 1600 R. P. M. Now, since sun gear 54 rotates with sun gear II and the ring gear 56 is at rest, the sun gear 54 drives the planet gears 52, and the latter acting through the stationary ring gear 56 as a fulcrum, produce cow. rotation of the carrier 50 at a speed one-fourth that of the sun gear 54, or at 400 R. P. M. Carrier 50 being keyed to shaft l4, rotates the latter at the same speed, with the result that the ring gear 41 also fixed to shaft (4, rotates ccw. at 400 R. P. M. Therefore, since sun gear 46 on input shaft I0 is rotating cw. at 1200 R. P. M., the planet gears 44 between sun gear 46 and ring gear 41 will revolve on their axes (shaft elements 43) without producing any rotation of the carrier 40. Hence, under these conditions the carrier 40 and the connected turbine driven structure 26 will remain at rest. At such time, the turbine impellers 32 although rotating with the input shaft at the indicated idling speed, are not rotating fast enough to cause displacement of the turbine driven struc- 168% 01 'Slmdiefate-propfirtidns toihold the turbine driven member against rotation with the turbine drivingniember.

-Where=the present transmission is provided in capacity suited to the --engine powerplant and normal expected driving load requirements of a g'iven automotive vehicle, for examplathe load imposed onthetransmissionoutput through connection-= thereof -w-i-th-the "vehicle drive wheels when the vehicleis a't-rest, i's 'sufficientat'engine idling -speed to' hold the turbine driven member against rotation. Consequently, the "vehicle-will remains at res't, that sp'ed reiationsiii o :bnea 11 th tain at any speed of the input sha ft It. ---Bi1t'-as-' transmission elements abeve mentioned;

the turbine driven -structure' accelerates fi'oin rest, resulting-inn -de'celeratio'n of the carrier fl to zero-speed and thence acceleration-in reverse rotation as indicated hereinbefore; the sun gear 54= becomes effective through the p1anet'-gears *5'2"- Whenon car'rier 5| to drive "the r'ing" gear "55.-

remain at' rest even-though the vehicledrive wheels areconnected to the engine outputshaft throughthe-transmission. Removal of the load, as by disconnection of 1 the --transm-ission output the ringgear 56 *isbhe-third thespeedor gear 54 and cw." because of the ccw. rotation-hf the sumg'ear. Therefore, the direction-ofrotatibrl Ofthe -Output shaft l I to which the ring gear is connected; is cw.

from the vehicle-drive wheels will, of COH-ISyfI-GH sion output shaft, suitable provision should be made for restraining V the output I shaft against rotation when 1oadconnection 'is-made-to the transmissiom inorder to avoid shock to the mechanism wh'ich would 1 occur otherwise, were the connection made to-the transmission -output shaft while it is rotating. A provision for this purpose is embodied in -thepresenttransmission, and such wi-ll be described hereinafter.

Up'on aec'elerat-ion-of -the-engine toward the indicated normal-operating speedof 24.04) RP. M., the "transmission functions in the following manner. 'As -acceleration-takes place, thefiuid-turbine "becomesefie'ctiveas atorque converter with fiu'idd'riveof the turbine driven structure 25 aided-by the reverse-flow produced by the reactor 2T -then constrained against reverse rotation by the one way brake 95. With rotation of'the turbine structure fifif the carrier 4t rotating therewith will cause the planet gears -44 acting through the sun-gear as a-fulcrum'to drive theringgear-t'l. Since under the idling condition -the ring-gear lllrotates ccw.,-it will be apparent that -with cw. rotation of sun gear "46 smi e-w: acceleration'pf-the-carrier 49, the ring gear w-ill"'deoelerate'- to zero-speedand thence accelerate in'the clockwise direction. The planet gear 'carrier tfl at 'the output" side of the transmissiom being connected to the shaft 14 to'which the ring gear 41 is connected, will follow exactly the deceleration and acceleration-displacements of ring gear 41, and its effect through the planet gears 52, on the output shaft I I will be described presently. *However, itis to=be noted; here that Rb'ta ting cw. I with the output-Shaft is' the Slim gear 66, and because "of the fixed axis of the gear 6! oonnectingthe sun g'eartt-and the ring-' ge'ar 88' of the double "ring gear unit 86; the gear 56 produoes ccw. rotation of the double 'ring-'=-'gear unit'86 at-a speed one-third that of the sun gear 66. ow the-sun gear 84' rotating at the speed of the "input shaft H3 anddriving-the gear =83 and hence" gear i9, cow. at thesaine' speedJfieb'ts the-= carrier 15 at one-third input speed. A's

before indicated, when ring *gear"unit"86-is =at rest, the planet gears 12 on -carr'ier 'iedrive the sun -gear H cow. at foiir" times the speed 7 of *the doublering gear unit '86; thesHn 'gear Il a-rid hencethe sun gear 5Q, will b'e -caused' to 'decelerate towardzero spee'df-the sun gear fidfhere cons tituting the effective output or terminal "element of the second 'line" of power transmissionin the present assembly.

' From the foregoing,- itwill -appear that upon increasein'speed of-the' input shaft ill from itsidling speed, the first line of power transmissidn through "the "assembly produces initially a 'proput shaft I l being greater with'decreasing' load- I the above described combined engine andturbine' drive of the carrier 50 constitutes one'line of power transmission in the presently improved transmission assembly.

Cooperating with the power drive-hereinabove described, is a second'combined drive involving gressive decrea'se l in 5 the speed of rotation of planet carrier 50, and thence a progressive inlines of 'transrnission thus'cooperatethrough the coaction of the sun'gear 5 l and the planet gears 52 on carrier"50,' to effect a resultant'cw. drive 50 of the ring gear 56 1 and hence; cw. drivefof' the output shaft ll. Moreover, the extent and-rate of speed change in respect to the speeds of carrier-50 and sun gear 54 during input shaft acceloration, will'depend upon theloading of the'outing, and less-with increasing loading.

-Upon"=d-eceleration of the input shaft, the" reverse of the" above takes placeand here'ag'ain; the rate and" extentof speed change in the sun gea'rt l and the carrier 50' depend onthe loadthesungear 8d driven from the input shaft l0 through the turbinecasing-3l, and the sun gear 66 connected throughthe drumlike member 22, to the output shaft 1 I. As before-indicated in the-description of the idling speedcondition of the transmission-wherein the output shaft l rand hence the ring gear56, is-at rest under load, the sun: gear 54 isdriven at one and-one-third the speed of the input shaft I Bjand drives the planet gear carrier 50 (through planet -gears 52) at a speed which is one-quarter of that of sun" gear ing. 'It will" appear now also, thatwith a -constant given speed of the input shaft, any change .i'gg the' above indicated manner; "While transmitting power from the input shaft i Bto the output altered conditions at the input Shaft'or the output shaft, or both. Assuming normal operation of the'transmission-system within its loadca pacity, *such'- adjustments serve to effect a "ba l 54: So J-long: as the turbine driven structure #35 75 anced c lrive', providing *a," speed} and torque out-- I 7 put matching the requirements of the load imposed on the output shaft of the transmission. In, all cases, the transmission adjustments occur smoothly and in step-less manner.

Accordingly, it will be now appreciated that the present transmission assembly affords a power drive connection between a source of power such as an internal combustion engine, and a load to be driven, wherein the turbomechanical gearing arrangement thereof is effec,

tive automatically without the aid of external controls, to produce an operating balance between the input torque and the load imposed on the transmission output shaft. Upon any change in the speed and torque of the input shaft I and/or in the load imposed on the output shaft II, the transmission gearing responds by corresponding relative adjustments of the cooperating lines of power flow therein, to attain such balanced drive.

An important feature of the present transmission is the over-drive function thereof. With the gear ratios assumed in the example hereinabove described, it will be evident that when the planet gear carrier 50 attains a speed equal to the speed of the input shaft I0, and the sun gear 54 reaches zero speed, the speed of the ring gear 56 and hence of the output shaft II, becomes one and one-third that of the input shaft speed. This obviously, is of great advantage where the transmission is employed in automotive vehicles. Moreover, it is now apparent that the speed and torque characteristics of the presently improved transmission, as well as the extent of overdrive thereof, may be determined through appropriate selection of gear ratios between the several sun and planet gear connections and between the planet gear and ring gear connections.

Since in the present transmission the output shaft II is constrained to a uni-directional rotation corresponding to the direction of input shaft rotation, as clockwise if the input shaft is driven clockwise, where drive reversal is desired or required as in automotive applications of the transmission, a suitable reverse gear unit may be employed between the transmission outputshaft II and the load. Such a unit is shown in the drawing at I00, having its gear case i0I supported on the transmission case wall 2i. Journalled at I02 and I04 in case It" is a shaft I05 which extends outwardly therefrom for connection to the load (not shown). The shaft I05 in its length between the bearings I02 and I04, is provided with splines I06, and axially slidable on the shaft in engagement with the splines thereof, is a double gear I08. Displacement of the gear I08 is here controlled through a shifting lever I09 in operative connection with the gear. Freely rotatable on shaft I05 near bearing I02, is a gear unit providing a sun gear H0 and as internal gear II2, the latter adapted for engagement by gearing II3 on double gear I08 when the double gear is shifted toward gear II2. Constantly enmeshing the sun gear I I0 is a gear II 4 keyed or otherwise secured to a countershaft IIG rotatably supported in the casing IOI and driven from the transmission output shaft II through connected gears H1 and H8. The countershaft IIG further has secured thereon within the reverse gear case I 0|, a sprocket I which is connected by a chain I2I to a similar sprocket I22 on a gear unit freely rotatably carried on the shaft I05 near bearing I04, the

gear unit providing the internal gear I24 en- Eel gageable by the gear I26 on the slide gear unit With the reverse gear provided as above described, it will be apparent that by shifting the gear unit I08 to engage its gear II3 with internal gear H2, the resulting drive of shaft I05 from,

the transmission output shaft II will be in the direction corresponding to the direction of 1'0? tation of shaft II. the gear unit I08 to engage its gear I26 with internal gear I24, will produce rotation of the shaft I05 in the reverse direction, while placement of the slide gear I08 out of engagement with either of the internal gears, determines verse gear unit I00, when the latter is in neutral. and the input shaft I0 is driven at any speed,;

say idling speed, the output shaft II will rotate correspondingly, since there is no load on the latter shaft. l-herefore, because the countershaft H8 is at all times in driven connection with the shaft H and, when rotating, produces rotation of the internal gears H2 andi24, shifting of the gear unit I08 to engage either gear II2 or I24 will result in gear clashing. Forcing of the gear connection in the reverse gear unit then would tend to subject the transmission to shock and possible damage.

tation while the reverse gear is shifted from neutral to forward or reverse drive conditions.

As presently indicated, such restraint of the countershaft may be efiected through the connected output shaft II and drum-like member 22 of the transmission, as by employing a suitable braking device or brake band I30 in ap- Actuplication to the periphery of member 22. ation of the brake band I30 may be effected through any suitable control means (not shown),

operable by the vehicle operator either directly or through the agency of say the service brakes of the vehicle. band I30 should be utilized only when the vehicle is substantially at rest and the transmission input shaft I0 is rotating at idling ora relatively low speed.

Having now described and illustrated a presently preferred embodiment of my invention,. what I desire to claim and secure by Letters.

Patent is:

l. A transmission interconnecting driving and :driven shafts, comprising a fluid turbine having driving and driven members, means connecting the turbine driving member to the driving shaft, differential gearing including a gear train connected to the turbine driving member and terminating in a sun gear, a gear element carriedon and operated by the driving shaft, said differential gearing providing a second gear train connected to said gear element and additionally connected to the turbine driven member, whereby the power input to the second gear train is' realized directly from the driving shaft through said gear element, and is further realized from. the turbine driven member, the second gear train terminating in planet gear means operatively engaging said sun gear, and means including a'rinz On the other hand, shifting.

In order to avoid such gear clashing and shock, the countershaft H8 is here constrained against ro-.

In any case, braking through gear engaging said planet gear means, operatively connecting the differential gearing to the driven shaft.

2. A transmission interconnecting driving and driven shafts, comprising differential gearing providing a terminal gear connected to the driven shaft and including a shaft element arranged longitudinally of the transmission, a fluid turbine having driving and driven members rotatably carried on said shaft element, an operative connection between the driving shaft and the turbine driving member, means connecting the turbine driving member to a gear element of the differential gearing, a sun gear carried on and operated by the driving shaft, a ring gear mounted on said shaft element for rotation therewith and constituting an element of said differential gearing, and planet gear means connected to the turbine driven member and operatively engaging said sun gear and said ring gear.

3. A transmission interconnecting driving and driven shafts, comprising differential gearing connected to the driven shaft and including a shaft element arranged longitudinally of the transmission, a fiuid turbine having driving and driven members and a reactor all rotatably carried on said shaft element, an operative connection between the driving shaft and the turbine driving member, means connecting the turbine driving member to a gear element of said differential gearing, a sun gear carried on and operated by the driving shaft, a ring gear connected to said shaft element and constituting an element of the differential gearing, planet gear means connected to the turbine driven member r and engaging said sun gear and ring gear, and means constraining said turbine reactor to a unidirectional rotation in the operation of the turbine.

a. A transmission interconnecting driving and driven shafts, comprising differential gearing including a shaft element arranged longitudinally of the transmission, a fluid turbine having driving and driven members rotatably supported by said shaft element, means operatively connecting the driving shaft and turbine driving member, a gear element rotatable on said shaft element, means connecting the turbine driving member to said gear element, a sun gear operated by the driving shaft, a ring gear connected to said shaft element and constituting an element of the differential gearing, planet gear means connected to the turbine driven member and engaging said sun gear and ring gear, said differential gearing further including a sun gear rotatable on said shaft element, means operatively connecting the last said sun gear and said gear element, planet gear means engaging the last said sun gear and in operative connection with said shaft element, and means including ring gear in engagement with the last said planet gear means, operatively connecting the differential gearing to the driven shaft.

5. A transmission interconnecting driving and driven shafts, comprising a fluid turbine having driving and driven members; means connecting the turbine driving member and the driving shaft; a first gear train including a gear element rotatable with said turbine driving member, a rotary planet gear carrier having planet gears thereon, a ring gear on said planet gear carrier, gear means interconnecting said ring gear and said gear element, and a terminal gear in operative connection with said planet gears; a second gear train including a rotary planet gear carrier connected to said turbine driven member, planet gears on said carrier, gear means in engagement with said planet gears, a second planet gear carrier and planet gears thereon in engagement with said terminal gear in the first said gear train, and means operatively connecting said gear means and said second planet gear carrier; and a rotatable member connected to the driven shaft of the transmission and providing a ring gear in engagement with the planet gears on the second planet gear carrier in said second gear train.

6. A transmission as defined by claim 5, characterized further by a sun gear operated by the driving shaft of the transmission and engaging the planet gears of the first said planet gear carrier in said second gear train.

7. A transmission as defined by claim 5, characterized further by gear means interconnecting said planet gears of the first said gear train and said rotatable member connected to the driven shaft of the transmission.

8. A transmission interconnecting driving and driven shafts, comprising a rotary shaft element arranged longitudinally in the transmission, a fluid turbine having driving and driven members rotatably supported on said shaft element, means operatively connecting the driving shaft and the turbine driving member, a sun gear driven by the driving shaft, a ring gear fixed on said shaft element, planet gear means connected to the turbine driven member and having the planet gears thereof in engagement with said sun gear and ring gear, a sun gear driven by the turbine driving member, a ring gear rotatable on said shaft element, gear means interconnecting the last said sun and ring gears, planet gears operatively carried on the last said ring gear, a tubular member rotatably sleeved on said shaft element, a sun gear fixed on said member and engaging the last said planet gears, a second sun gear fixed on said member, a gear member connected to the driven shaft of the transmission, and a planet gear carrier secured on said shaft element and supporting planet gears in engagement with said gear member and said second sun gear.

9. A transmission according to claim 8, characterized further by a gear element rotatable on a fixed axis, gear means connecting said gear element and the said gear member connected to the driven shaft of the transmission, and a double ring gear member rotatably supported on the said tubular member and having one ring gear thereof in engagement with said gear element, and the other ring gear thereof in engagement with the planet gears which are operatively carried on said ring gear rotatable on said shaft element.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 22,466 Pollard Apr. 4, 1944 2,196,585 Gette Apr. 9, 1940 2,431,318 Ellis Nov. 25, 1947 2,523,619 Grebb Sept. 26, 19-50 FOREIGN PATENTS Number Country Date 218,243 Switzerland Mar. 16, 1942 384,816 Great Britain Dec. 15, 1932 412,231 Great Britain June 22, 1934 

